This invention relates in general to vehicle weight or mass and, more particularly, to a method and apparatus for the automatic determination of the weight or mass of a moving vehicle.
The determination of the weight with regard to motor vehicles is of significance for a number of reasons. For example, it is important if the vehicle is driven by an internal combustion engine that is equipped with a transmission having staged gears. For proper gear changing control, a number of predetermined selection-criteria switching signals need to be generated. One selection-criteria being the weight or mass of the vehicle.
Prior to this invention, starting values corresponding with the starting torque of the combustion engine, and acceleration values corresponding with the acceleration of the vehicle, have been processed in an automatic calculating device. Also, other additional and desirable vehicle characteristic values regarding the operating condition of the vehicle for the purpose of determining the aforementioned switching signals have been processed in the calculating device setup. Furthermore, by way of a manually adjustable switch, normally in three stages, the calculating device setup is given additional essential information concerning the load condition of the vehicle as estimated by the driver.
The determination of the weight of a motor vehicle driven by an internal combustion engine, or a weight value corresponding with this weight is also necessary, for example, with an automatic load-dependent brake system. With such a system, the weight of the vehicle that is to be slowed down, or stopped, may be taken into consideration for proper brake application. Prior to this invention, for a reliable and accurate weight determination of the vehicle, one had to weigh the vehicle on a scale and transmit the thus determined weight to the setting member of the load-dependent brake system. Automatic load-dependent brake-force regulators, however, generally work with a lever mechanism which is logically arranged between the structure of the vehicle and an axle of the same, and is actuated in relationship to the load of the vehicle. Furthermore, if the vehicle is a truck, for example, the weight may change many times during the day due to loading and unloading of the truck contents. Therefore, in most cases, weighing the vehicle on a scale is not practical. In addition, the prior art devices for the automatic determination of the weight of a vehicle are either complicated or comparably expensive and inaccurate.